What will happen in this scenario?

A user has created a VPC with CIDR 20.0.0.0/16. The user has created one subnet with CIDR
20.0.0.0/16 in this VPC. The user is trying to create another subnet with the same VPC for CIDR
20.0.0.1/24. What will happen in this scenario?

A.
The VPC will modify the first subnet CIDR automatically to allow the second subnet IP range

B.
It is not possible to create a subnet with the same CIDR as VPC

C.
The second subnet will be created

D.
It will throw a CIDR overlaps error

Explanation:
A Virtual Private Cloud (VPC. is a virtual network dedicated to the user’s AWS account. A user can
create a subnet with VPC and launch instances inside that subnet. The user can create a subnet
with the same size of VPC. However, he cannot create any other subnet since the CIDR of the
second subnet will conflict with the first subnet.